


like any good big brother would

by WattStalf



Series: Commissions [153]
Category: Fire Emblem Series, Fire Emblem: If | Fire Emblem: Fates
Genre: F/M, Loss of Virginity, Sibling Incest, Unrequited Love, Vaginal Fingering, Vaginal Sex, commission
Language: English
Status: Completed
Published: 2020-08-10
Updated: 2020-08-10
Packaged: 2021-03-06 01:33:26
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,016
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25825168
Author URL: https://archiveofourown.org/users/WattStalf/pseuds/WattStalf
Summary: Elise is growing up, and Xander is not ready to let her go.
Relationships: Elise/Marx | Xander
Series: Commissions [153]
Series URL: https://archiveofourown.org/series/1325462
Comments: 3
Kudos: 16





	like any good big brother would

Xander knows that there will come a day that all of his siblings will grow up and go on to do their own things with their life. Part of being in the royal family involves dedicating their lives to whatever cause might benefit Nohr, and in most cases, that will involve marriages, often political and often loveless. He knows that that is something that will be expected even of him, and for the most part, he has come to terms with that with his siblings. There is just one sibling in particular that he has trouble accepting that with.

Really, when he thinks about it, it does not even matter if the marriage is political or not. Even if it is a loving marriage, with no ulterior motives, he thinks that he will feel the same way about it. The idea of seeing his youngest sister, of seeing Elise grow up and marry anyone is just too much for him to bear. Xander does not want to lose her to any man, even though he knows that one day, he is going to have to let her go. She is starting to grow up, after all, and that is just a part of growing up.

He has to find some way to make this all more bearable for him. He has to find a way to come to terms with what is happening, and to preserve his little sister in whatever way that he can. To him, Elise has always been the brightest, the most pure member of the family, and the idea of that light being taken away, and that purity being tainted by another man…he absolutely cannot allow it to happen, no matter what. But he knows that he can’t marry her for himself.

Even when he does not consider the great taboo that surrounds it, and the way he would be ruined as a ruler if anyone even suspected that he harbored such feelings for his sister, he still knows that it would not be possible. The family would gain no greater influence from such a marriage, and that would be not one, but two potential marriage candidates wasted on a marriage that Nohr will not benefit from. He knows that he will have to marry someone that will help expand their influence, and, if possible, Elise should be used as a similar bargaining chip. As much as that pains him to think about, he is a king first, and an older brother second.

So, then, would it be so wrong to let his feelings for his sister come first, if it is only for a night? Would it be so wrong for him to take what he wants most, and to make sure that, in some way, she will remain his, even after she has gone? Would it be so wrong for him to find a way to preserve the image of her purity in his mind, even if it is by taking her purity for himself?

Even as he ponders it, Xander already knows just how wrong it all is. No amount of justification can change what he is planning on doing to Elise, but still, he wants it so much that he is not able to talk himself out of it. He wants it so much that he will justify it in whatever way possible, the only way he can even attempt to satisfy his jealousy for a man that does not even exist yet, in a scenario that has not even come to pass yet. For just one night, he does not have to be the good king.

~X~

Elise answers his request to come to his room without question, the obedient little thing. He can hardly stand to think that she will be answering to another man someday, that she will be sharing a room with him, a bed…he needs to stop this train of thought before he is so frustrated that Elise is able to figure out that something is bothering him. She does not need to know the depths of his concerns when it comes to her future, partially because he does want her to think that there is anything to worry about, and partially because he does not want her to know just how pathetic of a brother he really is.

“What did you need, big brother?” she asks, with a smile so bright that it could stop his heart. There is no one in the world who deserves such pure radiance as Elise, he just knows it. Is he really supposed to let her go that easily? He deserves at least this much from her, even if he is never able to have anything else.

“I wanted to talk to you about your future,” he says, keeping his voice calm and level. “As you know, you are growing up more and more every day. There are certain…expectations that we will…” He trails off, not sure how he should word this, not sure how he should go about introducing what it is that he wants to do to her, all under the guise of it being in her best interest.

“Am I getting married?” she asks with wide eyes, and to hear her ask it, he nearly clutches his chest in surprise, even though that is part of what he has brought her hear to talk about. Not that she has a suitor waiting for her right this second or anything, but that is not too far off, he is certain.

“No, no, not that, not…yet,” he replies, still trying to gather his thoughts.

“Oh, okay! I thought you might have called me in here to break it to me gently that you’re marrying me off,” she says, with a dramatic sigh of relief. “But this is just you giving me a talk about how I’m going to have to get married someday, right? For the good of the kingdom?”

“It is…something like that, yes.” He takes a deep breath, preparing himself to launch into a complicated explanation, perhaps banking on the fact that he might be able to confuse her a bit, and get her to agree with what he wants without fully understanding it. How low he must have fallen, to be alright with manipulating his youngest sister like that!

“I already know all about that stuff. It’s all you hear about, growing up as a princess,” she replies, waving her hand dismissively. “I’m already fully prepared for whatever groom you might throw at me! Oh, just as long as it’s not Iago, or someone like that.” She wrinkles her nose at the thought, and Xander chuckles.

“I’m not marrying you off to Iago, I can promise you that much,” he replies, before clearing his throat. “Are you sure that you know…everything there is to know about it? Do you really think that you’re fully prepared? You know that you will be representing your entire family in everything that you do.”

“I know that, but…I mean, how hard can it be to be a good bride?” she asks, cocking her head.

“I…well, Elise. This is not an easy thing for me to ask, but do you know how to pleasure a man?” he asks very bluntly, hoping that getting to the heart of the matter, without hesitation, will do a good enough job of hiding how unsure of himself he really is right now. And to watch her face turn red, her mouth gaping open in surprise as she realizes what her stern older brother has asked her…oh, if only he could keep her for himself forever!

“Big brother, I…are you sure this is something we should be talking about? Isn’t this something that maybe, I don’t know, Camilla should be talking to me about?” she asks, biting her lip, trying to hide how shy the discussion is making her.

“I don’t think Camilla could really show you what to do,” he replies. “She isn’t a man, is she? There are things that you can only learn from experience, Elise. As your older brother, I…I want to be the one to teach you those things. Tonight, I want to give you that important lesson, for the…for the good of our family.” He knows that this is all bullshit, but he hopes that he is convincing, that Elise will not question him and that she will go through with it, because he is the older brother, and he knows best.

She is silent for a moment, gawking at him in shock. Maybe he should have built up to it a little more slowly. Right now, it seems as though she might die of shock, and that she is having a hard time processing anything that he has said to her. He gives her time, rather than assaulting her with more information, and finally, she stammers, “A-are we…are we going to have sex? B-big brother?”

His heart feels like it jumps into his throat; he swallows hard, to make sure that it stays where it belongs. “Yes, Elise. I want you to be ready for your future, so we’re going to have sex. I don’t want you to be left wondering what to do when the time comes, so as your big brother…”

She gives him a smile then, taking him by surprise. “Well, if I’ve got to do it with someone, I’d rather it be with you!” she declares, and he can hardly believe what he is hearing, that she is taking it all so casually. Perhaps there is some part of her that has wanted this, that has wanted _him_. Xander can hardly believe his good luck, and he tries to remain calm, so as not to give himself away.

No matter how much she might want this, he knows that he can’t do anything to expose that this was not about her future at all, but rather, to satisfy his own jealousy, to give himself a little peace of mind, to give himself what he has wanted for far too long. She has to think that this is a sacrifice on his part, even if she wants him, even if she has dreamed of this, which might not even be the case. He might just be looking too deep into her excitement, because he needs her to want him.

Xander gives Elise her first kiss then, to silence his own train of thought, his lips crashing down onto hers so suddenly that she whimpers into his mouth, an adorable squeak of surprise. He wraps his arms around her tiny shoulders, struck by just how small she is in comparison to him. She is growing up, and yet she seems to have hardly grown at all. Her mother was a small, frail woman, so he supposes that she takes after her, and will always be small.

Xander has grown to be just as big and imposing as the father that they share, while Elise is nothing like father. Out of his siblings, he seems to be the only one that has inherited anything from their father at all, but out of all of them, Elise remains the most radiant, the most pure. He wonders if that is part of what draws him to her, the way that she is nothing like what he has come to expect from the royal family. Elise has always been an outlier, and Xander has always been infatuated with her in one way or another, and now he is kissing her, ready to claim her virginity so that he can preserve her purity as something that belongs only to him.

Even knowing how fucked up his logic is, he is not able to stop himself, especially not when he is so close. She looks up at him, her eyes shining, when he breaks the kiss, and he knows that there is no turning back now, that she is going to be his. Without any further hesitation, he sets to undressing his little sister.

Sometimes it feels as though he is the only one that has grown, and right now, he can’t stop thinking about how small she feels in comparison to his hands, like he is getting bigger all the time, and Elise is staying the same tiny girl that he has always known. He is clumsy and awkward with removing her clothes, so she has him back off and deal with himself while she handles it, and when she is naked before him, he is almost in awe of how beautiful, of how pure, she is. She is all his now.

Xander sits on the edge of his bed and holds Elise on his lap, trying to ignore the comment she has made about how big he is. She giggles and that only flusters him further, wondering where on earth his sister learned to talk like that. All he can do is reach a hand between her legs, wanting to touch her at last, wanting to see if he can make her moan for him. She does have a point about his size, anyway, and he needs to do whatever he can to make sure that she can handle him, hesitating for only a moment before working a finger inside of her, listening to the way she squeaks at the sudden contact.

He is overwhelmed by her, by every sound and every move that she makes, and it is almost too much for him. If not for the fact that he knows this is going to be his only chance, the only time he will allow himself this indulgence, he would suggest that they take it slower, over the course of a few days, to give himself the chance he needs to adjust to it all. But he does not have that chance, and it has to be tonight, or else he will likely never be able to do this again. He has to take his one chance, powering on while Elise squirms in his lap, whimpering and then moaning, so adorable and so perfect that he knows this is what he was meant to do. She was meant to be his, at least once, even if it is only for tonight.

She should have been his forever.

As Xander fingers her, he imagines a world where her mother did not know who the father was, where her mother slept around rather than being so loyal and in love with their father. He imagines meeting Elise as the bastard of an unknown father, pushed into court to gain influence for her family. Though he knows he would not stand to gain much from that sort of marriage, he can’t help but imagine that he would have fallen for her then, that he would have seen the family resemblance and known her to be his sister, but that no one else would have known or questioned it, that he would have pretended to fall for the tricks of her family as he married her and made her his queen.

Instead, he is pinning his youngest sister to his bed, so that he can take her virginity and nothing else, and then marry her off to someone else and spend the rest of his days suffering in his private jealousy. Elise looks up at him, a mixture of nerves and excitement in her eyes, and he knows that he is taking advantage of her. He knows that, and that is still not enough to stop him from wanting this, and not enough to stop him from pushing down into her, making her squeak and whimper, growing tense in her discomfort, as Xander slowly fits his cock inside of her.

It takes her time to adjust to him, and even as he murmurs to her, telling her to relax, she still struggles a bit, tensing up when she does not intend to, until finally, he has fit himself inside of her completely, and she tries to catch her breath, gasping out. She moans for him, and says, “Big brother…I think I like this…”

Xander has never heard anything more beautiful in his entire life.

He loses himself in it then, and it takes Elise some effort to keep up with him. He would have wanted to be more gentle with her, but once he is here, he finds that he can’t slow down, thrusting wildly as he does what he can to claim her as his own, groaning and fucking her much harder than a delicate girl like her deserves. But still, Elise does not protest, just doing what she can to adjust before giving into her own moans. Maybe he can justify his rough treatment; maybe she needs to learn that not all mean are gentle, though he hates to imagine her being handed off to a husband that does not treat her like she is made of glass. He is such a damn hypocrite.

“I love you,” he whispers to her, his voice strained, as he leans down to put his lips near her ear. He is just barely holding on now, waiting until he feels her giving into pleasure, waiting until Elise comes for him, her strangled moans perhaps meant as a response to his confession, but not coherent enough to place. Only then does he make himself pull out of her. Tonight was risky enough as it is, he knows.

While they are both focused on catching their breath, he realizes that his confession meant nothing. Of course she knows that he loves her, as any good big brother would. To her, this has all been about him being a good big brother, and as far as she knows, she loves him too, just the way she should, as she should love any good big brother. Tonight, he could pretend that she was his, but he knows that she isn’t, that she never will be.

But, as any good big brother would, he allows himself to be content with what he has.

**Author's Note:**

> If you're interested in my writing updates, please follow my fanfiction twitter @WattStalf  
> 


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